package com.aqie.easy.binarySearch;

/**
 * 704 二分查找 15030879037
 */
public class Search {

    /**
     * 正规二分查找
     * @param nums
     * @param target
     * @return
     */
    public int search(int[] nums, int target) {
        int left = 0;
        int right = nums.length - 1;
        while (left <= right){
            int mid = left + (right - left) / 2;
            if (nums[mid] == target) return mid;
            else if (nums[mid] < target){
                left = mid + 1;
            }else if (nums[mid] > target){
                right = mid - 1;
            }
        }
        return -1;
    }

    /**
     * 寻找左侧边界
     * @param nums
     * @param target
     * @return
     */
    int left_bound(int[] nums, int target) {
        if (nums.length == 0) return -1;
        int left = 0;
        int right = nums.length; // 注意

        while (left < right) { // 注意
            int mid = (left + right) / 2;
            if (nums[mid] == target) {
                right = mid;
            } else if (nums[mid] < target) {
                left = mid + 1;
            } else if (nums[mid] > target) {
                right = mid; // 注意
            }
        }
        return left;
    }


    /**
     * 寻找右侧边界
     * @param nums
     * @param target
     * @return
     */
    int right_bound(int[] nums, int target) {
        if (nums.length == 0) return -1;
        int left = 0, right = nums.length;

        while (left < right) {
            int mid = (left + right) / 2;
            if (nums[mid] == target) {
                left = mid + 1; // 注意
            } else if (nums[mid] < target) {
                left = mid + 1;
            } else if (nums[mid] > target) {
                right = mid;
            }
        }
        return left - 1; // 注意
    }



    public static void main(String[] args) {
        String s = "15030879037";
    }
}
